US20020005092A1 - Hydraulic wrench control valve systems - Google Patents
Hydraulic wrench control valve systems Download PDFInfo
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- US20020005092A1 US20020005092A1 US09/847,697 US84769701A US2002005092A1 US 20020005092 A1 US20020005092 A1 US 20020005092A1 US 84769701 A US84769701 A US 84769701A US 2002005092 A1 US2002005092 A1 US 2002005092A1
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- pilot valve
- control valve
- pilot
- cylinder
- valve
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
- B25B21/00—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
- B25B21/00—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose
- B25B21/004—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose of the ratchet type
- B25B21/005—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose of the ratchet type driven by a radially acting hydraulic or pneumatic piston
Definitions
- the invention relates to valves in general, hydraulic valves in particular, and especially to a control valve for a hydraulic torque wrench with a hydraulic spin down motor.
- the invention is intended for use with a hydraulic torque wrench having a built in run down motor.
- the hydraulic torque wrench essentially comprises a drive head having a socket configured to engage a threaded member such as a bolt or a nut.
- the drive head has a plurality of ratchet teeth radially positioned on the drive head.
- a hydraulic cylinder is configured to extend and retract a drive pawl which engages the ratchet teeth upon extension and thus rotates the drive head. Rotation of the drive head results in the rotation of the socket and the threaded member which the socket has engaged.
- Very high pressures can be exerted against the drive head with the hydraulic cylinder, resulting in torques in the range of about 10,000 to upward of 34,000 ft. lbs. being applied to the threaded member being tightened or loosened. Examples of this type of torque wrench can be found in U.S. Pat. No. 4,448,096.
- the spin down motor is also preferably hydraulically driven. It is mechanically coupled to the drive head. Although the spin down motor is not configured to generate the very high torques that the hydraulic cylinder is designed to create, it is capable of rotating the drive head much faster than the hydraulic cylinder. In the preferred embodiment, the hydraulic spin down motor will typically generate about 500 ft lbs. of torque and rotate the drive head at about 585 rotations per minute (rpm's). Torque from spin down motor may be improved, at the price of speed, by adding pulleys or gears as disclosed in U.S. application Ser. No. 09/302,836.
- the spin down motor is used to either spin the threaded member into a snug position during make up or to spin the threaded member until it is nearly or fully disengaged during break out.
- torque wrench assemblies incorporating hydraulic spin down motors may be found in U.S. patent application Ser. No. 09/302,836 and in PCT/US94/14715.
- the valve of the present invention is configured to operate both the hydraulic torque wrench and the hydraulic spin down motor. It operates on a hydraulic system having pressurized line and a tank line.
- the pressurized line carries hydraulic fluid coming from the pump while the tank line returns the hydraulic fluid to the system reservoir.
- These lines enter the distribution block that houses the valve mechanism. They pass through a three position operator valve which controls how hydraulic fluid is directed through the combined wrench assembly.
- the operator valve has three positions. In its center position, position A, the hydraulic fluid flow to the rundown motor is cut off as is the flow to the extension side of the hydraulic cylinder, while the retraction side is pressurized. In the left position, position B, the rundown motor is pressurized as is the retraction side of the hydraulic cylinder, while the extension side remains cut off from pressure. In the right position, position C, the retraction side is cut off from hydraulic pressure as is the rundown motor, while the extension side of the of the hydraulic cylinder is pressurized.
- the operator valve is preferably biased with a spring or other means to return to center position A when released by the operator.
- FIG. 1 is a perspective view of a preferred embodiment of the wrench assembly engaged with a riser.
- FIG. 2 is a top view and partial cut-away of a preferred embodiment of the wrench assembly.
- FIG. 3 is schematic drawing of the hydraulics of a preferred embodiment of the invention using a single four way pilot valve.
- FIG. 4 is schematic drawing of the hydraulics of a preferred embodiment of the invention using two three way pilot valves.
- FIG. 5 is an exploded view of one preferred embodiment of a hydraulic wrench suitable for use with the hydraulic control valve disclosed herein.
- Hydraulic wrench assembly 1 comprises a drive head 2 having a socket 3 configured to engage a threaded member 4 , such as a nut or a bolt.
- Drive head 2 also comprises a plurality of ratchet teeth 5 radially positioned on drive head 2 .
- Hydraulic wrench assembly 1 further comprises a hydraulic cylinder 6 .
- Hydraulic cylinder 6 is configured to extend and retract a pawl 8 which is positioned to engage ratchet teeth 5 upon extension of pawl 8 .
- drive head 2 , socket 3 , and threaded member 4 may be rotated upon further extension of pawl 8 , which will either tighten or loosen threaded member 4 depending upon the direction of rotation of drive head 2 .
- Pawl 8 may retracted and extended again, further rotating drive head 3 , socket 3 , and threaded member 4 until the desired torque is reached or until threaded member 4 is adequately loosened.
- Hydraulic wrench assembly 1 further comprises a spin down motor 9 which is preferably hydraulically driven and should be mechanically coupled to drive head 2 so that operation of spin down motor 9 will result in drive head 2 , socket 3 , and threaded member 4 being rotated.
- spin down motor 9 will rotate at about 585 rpm and will be configured to provide about 500 ft lbs of torque to threaded member 4 .
- Spin down motor 9 will be used until threaded member 4 is snug, a condition that will be apparent when spin down motor 9 and drive head 2 stop turning.
- motor torque control valve 10 When the pressure in the hydraulic line reaches a preset level, motor torque control valve 10 will open and allow the hydraulic fluid to flow to tank, avoiding motor 9 . When this happens, motor 9 will stop turning. The torque exerted by motor 9 when the hydraulic pressure is sufficient to cause motor torque control valve 10 to open is the maximum torque that will be exerted by motor 9 with motor torque valve 10 in place. It is at this point that motor 9 is said to “torque out.” Additional tightening must be performed with hydraulic cylinder 6 .
- the maximum torque exerted by hydraulic cylinder 6 is controlled by a cylinder torque control valve 11 in much the same way that the torque exerted by motor 9 is controlled by motor torque control valve 10 .
- Cylinder 6 acts as a blockage in the hydraulic line feeding it. The pressure in the line and in cylinder 6 will increase until piston 12 moves, increasing the volume of cylinder 6 and relieving the pressure.
- cylinder 6 is extending pawl 8 against ratchet teeth 5 to turn drive head 2 and threaded member 4 , threaded member 4 will resist the extension of cylinder 6 .
- the speed of motor 9 or cylinder 6 may be controlled by a motor speed control valve 13 or a cylinder speed control valve 14 . Both valves 13 and 14 operate by restricting the rate at which fluid flows through the hydraulic lines to motor 9 or cylinder 6 . This will prevent cylinder 6 or motor 9 from extending, retracting or rotating too fast, which could lead to operator injury or to equipment damage. Speed control valves 13 and 14 should preferably be positioned downstream from motor torque control valve 10 or cylinder torque control valve 11 , respectively.
- the operation of wrench assembly 1 is controlled by a distribution block 7 from a three position operator control valve 15 .
- Operator control valve 15 has a center position A in which motor 9 and the extension side 16 of cylinder 6 are not pressurized and are connected to the tank and in which retraction side 17 of cylinder 6 is pressurized.
- Operator control valve 15 is preferably spring biased to return to center position A when it is released.
- Operator control valve 15 also has a left position B in which motor 9 and retraction side 17 of cylinder 6 are pressurized, and extension side 16 of cylinder 6 is connected to the tank.
- operator control valve 15 has a right position C in which extension side 16 of cylinder 6 is pressurized and retraction side 17 and motor 9 are connected to the tank.
- Distribution block 7 preferably contains a pressure line 18 and a tank line 19 .
- Pressure line 18 preferably has motor branch 18 A and a cylinder branch 18 B.
- Motor branch 18 A of pressure line 18 runs into operator control valve 15 .
- motor hydraulic line 20 which contains motor torque control valve 10 and motor speed control valve 13 .
- Motor hydraulic line 20 provides hydraulic fluid and pressure to motor 9 , causing motor 9 to run.
- Motor tank line 21 allows hydraulic fluid to flow out of motor 9 to tank line 19 .
- operator control valve 15 is in either center position A or right position C, motor hydraulic line 20 is connected to tank line 19 .
- motor 9 will not run.
- a pilot valve line 22 extends from operator control valve 15 to pilot valve 23 . Additionally, cylinder branch 18 B of pressure line 18 runs directly to pilot valve 23 without running through operational control valve 15 . Pilot valve 23 has a first position D and a second position E. Pilot valve is preferably biased with a spring or other means into first position D.
- a cylinder retraction line 24 and a cylinder extension line 25 extend from pilot valve 23 to retraction side 17 and extension side 16 of cylinder 6 , respectively.
- pilot valve 23 When pilot valve 23 is in first position D, pilot valve 23 connects extension line 25 with cylinder tank line 26 which is connected to tank line 19 .
- Pilot valve 23 also connects cylinder branch 18 B of pressure line 18 , which preferably contains cylinder torque control valve 11 and cylinder speed control valve 14 , with cylinder retraction line 24 , when pilot valve 23 is in first position D.
- cylinder branch 18 B of pressure line 18 which preferably contains cylinder torque control valve 11 and cylinder speed control valve 14
- pilot valve 23 When pilot valve 23 is in second position E, pilot valve 23 connects extension line 25 with cylinder branch 18 B of pressure line 18 and retraction line 24 with cylinder tank line 26 . Thus, when pilot valve 23 is in second position E, extension side 17 is pressurized and retraction side 16 is connected to the tank.
- pilot valve 23 is preferably spring biased into first position D.
- pilot valve line 22 When pilot valve line 22 is pressurized it will exert pressure against pilot valve 23 and, overriding the spring biasing, will move pilot valve 23 into second position E.
- pilot valve line 22 When operational control valve 15 is in center position A or left position B, pilot valve line 22 will be connected to tank line 19 . Thus, when operational control valve 15 is in either center position A or left position B, pilot valve line 22 will not be under pressure and pilot valve 23 will be in first position D. However, when operational control valve 15 is in right position C, pilot valve line 22 will be pressurized and pilot valve 23 will move into second position E. This will pressurize extension side 16 and connect retraction side 17 to tank line 19 , causing piston 12 and pawl 8 to be extended.
- pilot valve 23 is a four way directional control valve.
- pilot valve 23 may be a pair of three way directional control valves 23 A and 23 B.
- pilot valve line 22 will have a retraction branch 27 and an extension branch 28 .
- Retraction branch 27 will connect pilot valve line 22 to pilot valve 23 A and extension branch 28 will connect pilot valve line 22 to pilot valve 23 B.
- cylinder branch 18 B of pressure line 18 will have an extension branch 18 C and a retraction branch 18 D.
- Extension branch 18 C extends from cylinder branch 18 B to pilot valve 23 B and retraction branch 18 D extends from cylinder branch 18 B to pilot valve 23 A.
- Pilot valve 23 A is connected to retraction side 17 of cylinder 6 by cylinder retraction line 24
- pilot valve 23 B is connected to extension side 16 of cylinder 6 by cylinder extension line 25 . Pilot valves 23 A and 23 B control whether extension side 16 or retraction side 17 is pressurized.
- Pilot valves 23 A has a first position L and a second position M. Pilot valve 23 A is preferably spring biased to remain in first position L. When pilot valve 23 A is in first position L, pilot valve 23 A will connect retraction line 24 to retraction branch 18 D of pressure line 18 . Thus, when pilot valve 23 A is in first position L, retraction side 17 of cylinder 6 will be pressurized and piston 12 will be retracted.
- pilot valve 23 When pilot valve 23 is in second position M, pilot valve 23 A will connect retraction line 24 to tank line 19 . Thus, when pilot valve 23 A is in second position M, retraction side 17 of cylinder 6 will not be pressurized and piston 12 will be free to extend.
- Pilot valve 23 B also has a first position N and a second position O. Pilot valve 23 B is preferably spring biased to remain in first position N. When pilot valve 23 B is in first position N, pilot valve 23 B will connect extension line 25 to tank line 19 . Thus, when pilot valve 23 B is in first position N, extension side 16 of cylinder 6 will not be pressurized and piston 12 will be free to retract.
- pilot valve 23 B When pilot valve 23 B is in second position O, pilot valve 23 B will connect cylinder extension line 25 to extension branch 18 C of pressure line 18 . Thus, when pilot valve 23 B is in second position O, extension side 16 of cylinder 6 will be pressurized and piston 12 will extend.
- operator control valve 15 When operator control valve 15 is in center position A or left position B, operator control valve 15 will connect pilot valve line 22 , its retraction branch 27 , and its extension branch 28 to tank line 19 .
- pilot valve line 22 when operational control valve 15 is in either center position A or left position B, neither pilot valve line 22 nor its retraction and extension branches 27 and 28 will be under pressure, and pilot valves 23 A and 23 B will be in first positions L and N.
- pilot valve line 22 , it retraction branch 27 and its extension branch 28 will be pressurized and pilot valves 23 A and 23 B will move into second positions M and O.
- pilot valve 23 A when operational control valve 15 is in right position C, pilot valve 23 A will connect retraction line 24 to tank line 19 , and pilot valve 23 B will connect cylinder extension line 25 to extension branch 1 8 C of pressure line 18 . Therefore, when operational control valve 15 is in right position C, retraction side 17 of cylinder 6 will not be pressurized and extension side 16 of cylinder 6 will be pressurized, resulting in the extension of piston 12 .
- distribution block 7 will preferably be mounted on wrench assembly 1 .
- wrench assembly 1 When wrench assembly 1 is used on an oil rig, the rig hydraulic lines will engage pressure line 18 and tank line 19 . The operator will engage threaded member 4 with socket 3 of drive head 2 .
- the operator will move operator control valve 15 from center position A to left position B. This will direct hydraulic fluid from pressure line 18 into motor branch 18 A and on into spin down motor 9 .
- spin down motor 9 When pressurized, spin down motor 9 will rotate, thereby turning socket 3 and threaded member 4 until spin down motor 9 torques out.
- the operator When this happens, the operator will move operator control valve 15 into right position C. This will pressurize pilot valve line 22 and its extension and retraction branches 27 and 28 , if present.
- pilot valve 23 This will move pilot valve 23 from first position D to second position E or pilot valves 23 A and 23 B from first positions L and N to second positions M and O.
- pilot valve 23 or pilot valves 23 A and 23 B When pilot valve 23 or pilot valves 23 A and 23 B are in second positions E or M and O, hydraulic fluid will be directed to extension side 16 of cylinder 6 and retraction side 17 will be connected to tank line 19 .
- operator control valve 15 when operator control valve 15 is in right position C, piston 12 and pawl 8 will extend and pawl 8 will engage ratchet teeth 5 , turning drive head 2 , socket 3 , and threaded member 4 . This will continue until piston 12 is fully extended.
Abstract
Description
- This application claims benefit of provisional application No. 60/201,434, which was filed on May 3, 2000, and which is hereby incorporated by reference in its entirety.
- 1. Field of the Invention
- The invention relates to valves in general, hydraulic valves in particular, and especially to a control valve for a hydraulic torque wrench with a hydraulic spin down motor.
- 2. Prior Art
- The use of hydraulic wrenches to tighten (make up) or loosen (break out) nuts or I bolts in high torque applications, such as the erection of off shore risers is well known. See, e.g., U.S. Pat. No. 4,448,096, which is hereby incorporated by reference. These wrenches are well suited to the task of supplying the high torques needed in these applications, however, they are very slow in turning the bolt or nut being tightened or loosened. This is not a problem when the nut or bolt is snug, as very little additional rotation (≲1 full rotation) is all that is usually required to either reach the desired torque or to loosen the nut/bolt to the point that the high torque wrench is no longer needed to turn the nut/bolt. However, when the nut or bolt is not snug, the hydraulic torque wrench can be painfully slow. In the prior art, hydraulic torque wrenches were frequently removed after the bolt/nut was loosened and a low torque spin down wrench would then be used to back the bolt/nut out. Similarly, the low torque spin down wrench might be used to spin the bolt/nut down until it was snug, and then the hydraulic torque wrench would be used to fully tighten the bolt/nut. These wrenches are typically quite large, and changing them out constantly during a job can be expensive and time consuming. In response to these inconveniences, hydraulic torque wrenches that included a self-contained spin down motor were developed. See, e.g., U.S. patent application Ser. No. 09/302,836, which is hereby incorporated by reference in its entirety. However, the prior art combined wrenches, such as that disclosed in PCT/US94/14715, had numerous problems. Some of the problems included complicated and expensive hydraulic controls, troublesome back pressure valves, and an inability to use hydraulic sources already in place, such as the drilling rig hydraulic lines. Accordingly, a hydraulic control system that meets the following objects is desired.
- It is an object of the invention to provide a control system for a combination hydraulic torque wrench and spin down motor.
- It is an object of the invention to provide a control system for a combination hydraulic torque wrench and spin down motor which will only run the spin down motor when the hydraulic torque wrench is retracted.
- It is an object of the invention to provide a control system for a combination hydraulic torque wrench and spin down motor that will only extend the hydraulic torque wrench when the spin down motor is off.
- It is an object of the invention to provide a control system for a combination hydraulic torque wrench and spin down motor that does not require a back pressure valve.
- It is an object of the invention to provide a control system for a combination hydraulic wrench and spin down motor that will operate on rig hydraulics.
- It is an object of the invention to provide a control system for a combination hydraulic torque wrench and spin down motor that does not require a control console separate from the wrench.
- The invention is intended for use with a hydraulic torque wrench having a built in run down motor. The hydraulic torque wrench essentially comprises a drive head having a socket configured to engage a threaded member such as a bolt or a nut. The drive head has a plurality of ratchet teeth radially positioned on the drive head. A hydraulic cylinder is configured to extend and retract a drive pawl which engages the ratchet teeth upon extension and thus rotates the drive head. Rotation of the drive head results in the rotation of the socket and the threaded member which the socket has engaged. Very high pressures can be exerted against the drive head with the hydraulic cylinder, resulting in torques in the range of about 10,000 to upward of 34,000 ft. lbs. being applied to the threaded member being tightened or loosened. Examples of this type of torque wrench can be found in U.S. Pat. No. 4,448,096.
- The spin down motor is also preferably hydraulically driven. It is mechanically coupled to the drive head. Although the spin down motor is not configured to generate the very high torques that the hydraulic cylinder is designed to create, it is capable of rotating the drive head much faster than the hydraulic cylinder. In the preferred embodiment, the hydraulic spin down motor will typically generate about 500 ft lbs. of torque and rotate the drive head at about 585 rotations per minute (rpm's). Torque from spin down motor may be improved, at the price of speed, by adding pulleys or gears as disclosed in U.S. application Ser. No. 09/302,836. The spin down motor is used to either spin the threaded member into a snug position during make up or to spin the threaded member until it is nearly or fully disengaged during break out. Examples of torque wrench assemblies incorporating hydraulic spin down motors may be found in U.S. patent application Ser. No. 09/302,836 and in PCT/US94/14715.
- The valve of the present invention is configured to operate both the hydraulic torque wrench and the hydraulic spin down motor. It operates on a hydraulic system having pressurized line and a tank line. The pressurized line carries hydraulic fluid coming from the pump while the tank line returns the hydraulic fluid to the system reservoir. These lines enter the distribution block that houses the valve mechanism. They pass through a three position operator valve which controls how hydraulic fluid is directed through the combined wrench assembly.
- The operator valve has three positions. In its center position, position A, the hydraulic fluid flow to the rundown motor is cut off as is the flow to the extension side of the hydraulic cylinder, while the retraction side is pressurized. In the left position, position B, the rundown motor is pressurized as is the retraction side of the hydraulic cylinder, while the extension side remains cut off from pressure. In the right position, position C, the retraction side is cut off from hydraulic pressure as is the rundown motor, while the extension side of the of the hydraulic cylinder is pressurized. The operator valve is preferably biased with a spring or other means to return to center position A when released by the operator. The preferred mechanisms for routing the hydraulic fluid through the distribution block to achieve the results described above is set forth in the detailed description of the preferred embodiment below.
- FIG. 1 is a perspective view of a preferred embodiment of the wrench assembly engaged with a riser.
- FIG. 2 is a top view and partial cut-away of a preferred embodiment of the wrench assembly.
- FIG. 3 is schematic drawing of the hydraulics of a preferred embodiment of the invention using a single four way pilot valve.
- FIG. 4 is schematic drawing of the hydraulics of a preferred embodiment of the invention using two three way pilot valves.
- FIG. 5 is an exploded view of one preferred embodiment of a hydraulic wrench suitable for use with the hydraulic control valve disclosed herein.
-
Hydraulic wrench assembly 1 comprises adrive head 2 having asocket 3 configured to engage a threadedmember 4, such as a nut or a bolt. Drivehead 2 also comprises a plurality ofratchet teeth 5 radially positioned ondrive head 2.Hydraulic wrench assembly 1 further comprises ahydraulic cylinder 6.Hydraulic cylinder 6 is configured to extend and retract apawl 8 which is positioned to engageratchet teeth 5 upon extension ofpawl 8. When pawl 8 engages ratchetteeth 5,drive head 2,socket 3, and threadedmember 4 may be rotated upon further extension ofpawl 8, which will either tighten or loosen threadedmember 4 depending upon the direction of rotation ofdrive head 2.Pawl 8 may retracted and extended again, further rotatingdrive head 3,socket 3, and threadedmember 4 until the desired torque is reached or until threadedmember 4 is adequately loosened. -
Hydraulic wrench assembly 1 further comprises a spin downmotor 9 which is preferably hydraulically driven and should be mechanically coupled to drivehead 2 so that operation of spin downmotor 9 will result indrive head 2,socket 3, and threadedmember 4 being rotated. Typically, spin downmotor 9 will rotate at about 585 rpm and will be configured to provide about 500 ft lbs of torque to threadedmember 4. Spin downmotor 9 will be used until threadedmember 4 is snug, a condition that will be apparent when spin downmotor 9 and drivehead 2 stop turning. - Spin down
motor 9 will stop turning when it “torques out.” Hydraulic spin downmotor 9 acts as blockage in the hydraulic line feeding it. As the pressure builds up, the pressurized fluid causes motor 9 to rotate which allows the fluid to pass and prevents the pressure from building up further. However, if something preventsmotor 9 from rotating, the pressure will continue to increase until either that obstacle is overcome andmotor 9 rotates allowing some of the fluid to pass or until relief is obtained elsewhere. As threadedmember 4 gets tighter, it will obviously provide more and more resistance to the rotation ofmotor 9. Thus, as threadedmember 4 gets tighter and tighter, the pressure in the hydraulic line will be forced ever higher. Relief is provided by motortorque control valve 10, which is set to open a predetermined pressure. When the pressure in the hydraulic line reaches a preset level, motortorque control valve 10 will open and allow the hydraulic fluid to flow to tank, avoidingmotor 9. When this happens,motor 9 will stop turning. The torque exerted bymotor 9 when the hydraulic pressure is sufficient to cause motortorque control valve 10 to open is the maximum torque that will be exerted bymotor 9 withmotor torque valve 10 in place. It is at this point thatmotor 9 is said to “torque out.” Additional tightening must be performed withhydraulic cylinder 6. - The maximum torque exerted by
hydraulic cylinder 6 is controlled by a cylindertorque control valve 11 in much the same way that the torque exerted bymotor 9 is controlled by motortorque control valve 10.Cylinder 6 acts as a blockage in the hydraulic line feeding it. The pressure in the line and incylinder 6 will increase untilpiston 12 moves, increasing the volume ofcylinder 6 and relieving the pressure. Whencylinder 6 is extendingpawl 8 againstratchet teeth 5 to turndrive head 2 and threadedmember 4, threadedmember 4 will resist the extension ofcylinder 6. When this happens, the pressure in the hydraulic line and incylinder 6 will continue to increase until sufficient torque is generated to overcome the resistance of threadedmember 4, at whichpoint drive head 4 and threadedmember 4 will be rotated, further tightening threadedmember 4 and increasing the torque needed to tighten threadedmember 4 further. As this continues, the pressure in the hydraulic line will continue to increase until the pressure is sufficient to open cylindertorque control valve 11. When this happens,piston 12 ofcylinder 6 can be extended no further, andcylinder 6 is said to have “torqued out.” - The torque exerted by
motor 9 andcylinder 6 for each pound per square inch of pressure in the hydraulic lines can be calibrated. These figures will vary with individual hydraulic components, and should be readily obtainable from the manufacturer of the part. Once it is known, the maximum torque exerted by either component ofwrench assembly 1 may set by the operator simply by adjusting the pressure at which motortorque control valve 10 or cylindertorque control valve 11 will open. - The speed of
motor 9 orcylinder 6 may be controlled by a motorspeed control valve 13 or a cylinderspeed control valve 14. Bothvalves motor 9 orcylinder 6. This will preventcylinder 6 ormotor 9 from extending, retracting or rotating too fast, which could lead to operator injury or to equipment damage.Speed control valves torque control valve 10 or cylindertorque control valve 11, respectively. - The operation of
wrench assembly 1 is controlled by adistribution block 7 from a three positionoperator control valve 15.Operator control valve 15 has a center position A in whichmotor 9 and theextension side 16 ofcylinder 6 are not pressurized and are connected to the tank and in whichretraction side 17 ofcylinder 6 is pressurized.Operator control valve 15 is preferably spring biased to return to center position A when it is released.Operator control valve 15 also has a left position B in whichmotor 9 andretraction side 17 ofcylinder 6 are pressurized, andextension side 16 ofcylinder 6 is connected to the tank. Finally,operator control valve 15 has a right position C in whichextension side 16 ofcylinder 6 is pressurized andretraction side 17 andmotor 9 are connected to the tank. -
Distribution block 7 preferably contains apressure line 18 and atank line 19.Pressure line 18 preferably hasmotor branch 18A and acylinder branch 18B.Motor branch 18A ofpressure line 18 runs intooperator control valve 15. Whenoperator control valve 15 is in left position B,motor branch 18A is connected to motorhydraulic line 20 which contains motortorque control valve 10 and motorspeed control valve 13. Motorhydraulic line 20 provides hydraulic fluid and pressure tomotor 9, causingmotor 9 to run.Motor tank line 21 allows hydraulic fluid to flow out ofmotor 9 totank line 19. Whenoperator control valve 15 is in either center position A or right position C, motorhydraulic line 20 is connected totank line 19. Thus, whenoperator control valve 15 is in either position A or C,motor 9 will not run. - In one preferred embodiment, a
pilot valve line 22 extends fromoperator control valve 15 topilot valve 23. Additionally,cylinder branch 18B ofpressure line 18 runs directly topilot valve 23 without running throughoperational control valve 15.Pilot valve 23 has a first position D and a second position E. Pilot valve is preferably biased with a spring or other means into first position D. - A
cylinder retraction line 24 and acylinder extension line 25 extend frompilot valve 23 toretraction side 17 andextension side 16 ofcylinder 6, respectively. Whenpilot valve 23 is in first position D,pilot valve 23 connectsextension line 25 withcylinder tank line 26 which is connected totank line 19.Pilot valve 23 also connectscylinder branch 18B ofpressure line 18, which preferably contains cylindertorque control valve 11 and cylinderspeed control valve 14, withcylinder retraction line 24, whenpilot valve 23 is in first position D. Thus, whenpilot valve 23 is in first position D,retraction side 17 ofcylinder 6 is pressurized andextension side 16 is connected to the tank. - When
pilot valve 23 is in second position E,pilot valve 23 connectsextension line 25 withcylinder branch 18B ofpressure line 18 andretraction line 24 withcylinder tank line 26. Thus, whenpilot valve 23 is in second position E,extension side 17 is pressurized andretraction side 16 is connected to the tank. - As stated above,
pilot valve 23 is preferably spring biased into first position D. Whenpilot valve line 22 is pressurized it will exert pressure againstpilot valve 23 and, overriding the spring biasing, will movepilot valve 23 into second position E. - When
operational control valve 15 is in center position A or left position B,pilot valve line 22 will be connected totank line 19. Thus, whenoperational control valve 15 is in either center position A or left position B,pilot valve line 22 will not be under pressure andpilot valve 23 will be in first position D. However, whenoperational control valve 15 is in right position C,pilot valve line 22 will be pressurized andpilot valve 23 will move into second position E. This will pressurizeextension side 16 and connectretraction side 17 totank line 19, causingpiston 12 andpawl 8 to be extended. - In the embodiment described above,
pilot valve 23 is a four way directional control valve. However, in another embodiment, principally for use when space is at a premium,pilot valve 23 may be a pair of three waydirectional control valves pilot valve line 22 will have aretraction branch 27 and anextension branch 28.Retraction branch 27 will connectpilot valve line 22 to pilotvalve 23A andextension branch 28 will connectpilot valve line 22 topilot valve 23B. Additionally,cylinder branch 18B ofpressure line 18, will have anextension branch 18C and aretraction branch 18D.Extension branch 18C extends fromcylinder branch 18B topilot valve 23B andretraction branch 18D extends fromcylinder branch 18B to pilotvalve 23A.Pilot valve 23A is connected toretraction side 17 ofcylinder 6 bycylinder retraction line 24, andpilot valve 23B is connected toextension side 16 ofcylinder 6 bycylinder extension line 25.Pilot valves extension side 16 orretraction side 17 is pressurized. -
Pilot valves 23A has a first position L and a second positionM. Pilot valve 23A is preferably spring biased to remain in first position L. Whenpilot valve 23A is in first position L,pilot valve 23A will connectretraction line 24 toretraction branch 18D ofpressure line 18. Thus, whenpilot valve 23A is in first position L,retraction side 17 ofcylinder 6 will be pressurized andpiston 12 will be retracted. - When
pilot valve 23 is in second position M,pilot valve 23A will connectretraction line 24 totank line 19. Thus, whenpilot valve 23A is in second position M,retraction side 17 ofcylinder 6 will not be pressurized andpiston 12 will be free to extend. -
Pilot valve 23B also has a first position N and a second positionO. Pilot valve 23B is preferably spring biased to remain in first position N. Whenpilot valve 23B is in first position N,pilot valve 23B will connectextension line 25 totank line 19. Thus, whenpilot valve 23B is in first position N,extension side 16 ofcylinder 6 will not be pressurized andpiston 12 will be free to retract. - When
pilot valve 23B is in second position O,pilot valve 23B will connectcylinder extension line 25 toextension branch 18C ofpressure line 18. Thus, whenpilot valve 23B is in second position O,extension side 16 ofcylinder 6 will be pressurized andpiston 12 will extend. - When
operator control valve 15 is in center position A or left position B,operator control valve 15 will connectpilot valve line 22, itsretraction branch 27, and itsextension branch 28 totank line 19. Thus, whenoperational control valve 15 is in either center position A or left position B, neitherpilot valve line 22 nor its retraction andextension branches pilot valves operational control valve 15 is in right position C,pilot valve line 22, itretraction branch 27 and itsextension branch 28 will be pressurized andpilot valves operational control valve 15 is in right position C,pilot valve 23A will connectretraction line 24 totank line 19, andpilot valve 23B will connectcylinder extension line 25 toextension branch 1 8C ofpressure line 18. Therefore, whenoperational control valve 15 is in right position C,retraction side 17 ofcylinder 6 will not be pressurized andextension side 16 ofcylinder 6 will be pressurized, resulting in the extension ofpiston 12. - In operation,
distribution block 7 will preferably be mounted onwrench assembly 1. Whenwrench assembly 1 is used on an oil rig, the rig hydraulic lines will engagepressure line 18 andtank line 19. The operator will engage threadedmember 4 withsocket 3 ofdrive head 2. During make up, the operator will moveoperator control valve 15 from center position A to left position B. This will direct hydraulic fluid frompressure line 18 intomotor branch 18A and on into spin downmotor 9. When pressurized, spin downmotor 9 will rotate, thereby turningsocket 3 and threadedmember 4 until spin downmotor 9 torques out. When this happens, the operator will moveoperator control valve 15 into right position C. This will pressurizepilot valve line 22 and its extension andretraction branches pilot valve 23 from first position D to second position E orpilot valves pilot valve 23 orpilot valves extension side 16 ofcylinder 6 andretraction side 17 will be connected totank line 19. Thus, whenoperator control valve 15 is in right position C,piston 12 andpawl 8 will extend andpawl 8 will engage ratchetteeth 5, turningdrive head 2,socket 3, and threadedmember 4. This will continue untilpiston 12 is fully extended. - When
piston 12 is fully extended, the operator will returnoperator control valve 15 to center position A. This will connectpilot valve line 22 and its extension andretraction branches tank line 19. In the absence of pressure inpilot valve line 22 or in extension orretraction branches pilot valve 23 orpilot valves retraction side 17 ofcylinder 6 while extension side will be connected totank line 19. Thus, whenoperator control valve 15 is in center position A,piston 12 andpawl 8 will retract out of engagement withratchet teeth 5. When pawl 8 has fully disengagedratchet teeth 5, the operator may returnoperator control valve 15 to right position C, and repeat the process untilcylinder 6 torques out.
Claims (24)
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US09/847,697 US6553873B2 (en) | 2000-05-03 | 2001-05-02 | Hydraulic wrench control valve systems |
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US20143400P | 2000-05-03 | 2000-05-03 | |
US09/847,697 US6553873B2 (en) | 2000-05-03 | 2001-05-02 | Hydraulic wrench control valve systems |
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US20020005092A1 true US20020005092A1 (en) | 2002-01-17 |
US6553873B2 US6553873B2 (en) | 2003-04-29 |
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